UV-curable polyurethane dispersions

Abstract

The invention relates to novel UV-curable polyurethane dispersions based on unsaturated polyesters modified with dicyclopentadiene, the preparation of these polyurethane dispersions and the use thereof as a lacquer, coating and/or adhesive.

1 . An aqueous polyurethane dispersion prepared from unsaturated polyester resins modified with dicyclopentadiene. 
     
     
         2 . An aqueous polyurethane dispersion according to  claim 1 , wherein the polyurethane is the reaction product of
 a) at least one unsaturated polyester resin modified with   dicyclopentadiene,   b) at least one at least difunctional polyisocyanate and   c) at least one hydrophilizing component.   
     
     
         3 . An aqueous polyurethane dispersion according to  claim 1 , wherein the polyurethane is the reaction product of
 a) at least one unsaturated polyester resin modified with dicyclopentadiene,   b) at least one at least difunctional polyisocyanate,   c) at least one hydrophilizing component having at least one hydroxyl, amino and/or thio group and at least one ionic or potentially ionic group and/or ethylene oxide, ethylene oxide/propylene oxide copolymer and/or block copolymer structural units,   d) at least one component selected from the group consisting of (poly)ester (meth)acrylates, (poly)ether (meth)acrylates, (poly)urethane (meth)acrylates, (poly)epoxy(meth)acrylates, (poly)ether ester (meth)acrylates and unsaturated polyesters having allyl ether structural units,   e) optionally hydroxy-functional diols and/or triols of number average molecular weight 62 to 242 and/or hydroxy-functional oligomers or polymers selected from the group consisting of polyesters, polycarbonates, polyurethanes, C2-, C3- and/or C4-polyethers, polyether esters and polycarbonate polyesters of number-average molecular weight 700 to 4,000 g/mol and   f) at least one mono-, di- and/or polyamine and/or hydroxyamine.   
     
     
         4 . An aqueous polyurethane dispersion according to  claim 3 , wherein
 component a) is at least one unsaturated polyester resin which is modified with 5 to 35 wt. % of dicyclopentadiene,   component b) is at least one at least difunctional polyisocyanate which comprises at least 60 wt. % aliphatic and/or cycloaliphatic polyisocyanates,   component d) is at least one compound chosen from the group consisting of polyester acrylates, polyether acrylates, polyepoxyacrylates, urethane acrylates and/or polyether ester acrylates, which also contains hydroxyl groups in addition to the unsaturated groups.   
     
     
         5 . An aqueous polyurethane dispersion according to  claim 1 , wherein the polyurethane is further prepared from at least one initiator and optionally auxiliary substances and additives which allow the polyurethane to be cured with UV radiation. 
     
     
         6 . An aqueous polyurethane dispersion according to  claim 3 , wherein the polyurethane is the reaction product of
 3 to 50 wt. % of component a), 7 to 50 wt. % of component b), 1 to 25 wt. % of component c), 10 to 75 wt. % of component d), 0 to 40 wt. % of component e) and 0.1 to 6 wt. % of component f),   the percentages of a) to f) adding up to 100 wt. %.   
     
     
         7 . An aqueous polyurethane dispersion according to  claim 1 , wherein the dispersion contains less than 5 wt. % of organic solvents. 
     
     
         8 . A process for the preparation of the polyurethane dispersion according to  claim 3 , comprising forming an isocyanate-functional prepolymer by reacting components a), c), optionally d) and e) with an excess of component b) in one or more reaction steps, adding a neutralizing agent for producing the ionic groups necessary for the dispersing to the reactants before, during or after this prepolymer formation, dispersing the prepolymer in water, optionally chain extending the prepolymer by adding component f). 
     
     
         9 . A binder mixture comprising a polyurethane dispersion according to  claim 1 . 
     
     
         10 . A coating composition comprising a polyurethane dispersion according to  claim 1  and a crosslinking agent.